1. Field of the Invention
This invention relates to tables. More particularly, this invention relates to tables having adjustable legs.
2. Description of the Prior Art
It is known to provide tables with adjustable legs. Examples of such tables are described in U.S. Pat. No. 4,237,795, U.S. Pat. No. 4,259,909, U.S. Pat. No. 4,273,306 and U.S. Pat. No. 5,649,493. In these known tables the adjustment mechanisms are designed such that the legs are all moved together to vary the height of the table top.
Viewed from one aspect the present invention provides a table comprising:
(i) a table top;
(ii) at least one adjustable leg pivotally attached to said table top; and
(iii) an adjuster for independently adjusting each adjustable leg, said adjuster being pivotally attached to said table top and said adjustable leg; wherein
(iv) said adjuster can be varied to adjust the angle between said adjustable leg and said table top thereby varying the height and angle of said table top such that said table can be levelled on uneven ground.
The invention recognises that in certain circumstances it is highly desirable that the adjustable legs should be able to move independently of one another so as to compensate for uneven ground. In this way, the legs may be independently adjusted so that they all contact the ground with the table level, firm and at the desired height. An example of a circumstance where this facility is highly advantageous is upon the deck of a boat. Boat decks frequently do not have a single level area of sufficient size to accommodate a table, but rather are characterised by many small stepped and shelved areas that can separately support a leg of the table providing the leg can be appropriately adjusted.
The adjuster could take many forms. However, in preferred embodiments said adjustable leg pivots in a single plane and said adjuster is a variable length strut with one end pivotally attached to said table top and the other end pivotally attached to said adjustable leg.
Providing an adjustable leg that pivots only in a single plane together with a variable length strut performing the role of the adjuster provides an advantageously simple and effective implementation.
The variable length strut can in turn be implemented in many different ways. However, in preferred embodiments of the invention said variable length strut comprises a central sleeve receiving at its threaded ends oppositely threaded coaxial rods, each said rod being pivotally attached to a respective one of said table top and said adjustable leg such that rotation of said sleeve relative to said rods either draws said rods together or forces said rods apart thereby shortening or lengthening said variable length strut.
The use of a threaded sleeve receiving oppositely handed threaded rods provides a very direct and robust mechanism for implementing the adjuster.
In order to improve the ease of use of the table said sleeve is positioned outwardly of said adjustable leg. Positioning the sleeve outwardly of the adjustable leg allows a user to more easily reach under the edge of the table from above and twist the sleeve to make the adjustment to the leg without having to turn the table over or crawl underneath the table.
In order to facilitate the table top being able to bear the loads placed upon it by the adjustable leg mechanisms, it is preferred that said table top comprises a table surface attached to a table top frame, said adjustable leg and said adjuster being attached to said table top frame.
A mechanically efficient and effective way of providing a table top frame to support the various parts of the table mechanism is one in which said table top frame includes a cross brace at a corner, said adjustable leg being attached to said cross brace and said adjuster being attached to said corner.
Whilst it will be appreciated that it may be possible to gain most of the advantages of the invention without having all of the legs of the table adjustable (e.g. a single fixed leg), it is strongly advantageous that all of the legs of said table are adjustable legs.
Whilst the table could have three legs, five legs or more, it has been found most practical and useful to employ the invention in embodiments in which said table has four legs.